Hybrid still/video cameras can be used to record both video and still pictures. Due to the demands for low cost, low power devices that can both (i) capture video at high resolutions and frame rates and (ii) capture still pictures at high speeds, the use of dedicated processing hardware is an attractive option for camera makers as dedicated hardware is commonly cheaper and more power efficient than general purpose processors.
Some processing criteria for video and still pictures are identical, for example demosaic processing. However, other processing criteria for still pictures and video differ. For example, video is captured “live” and so having multiple dedicated hardware circuits to generate multiple resolutions of each frame/field can be helpful. The multiple resolutions of the same frame/field could be used for all or some of: (i) generating a preview picture presented to a television monitor, (ii) generating a preview picture shown on a built-in display on the camera and (iii) generating a reduced resolution stream for dual stream recording (i.e., recoding at 1920×1080 pixels and 640×480 pixels; the latter being used for easy sharing over the Internet). In contrast, still picture processing typically includes a single preview picture at the resolution of the built-in display.
The temporal nature of video compared with the static nature of still pictures also results in different processing. In particular, video processing for good low light performance can include Motion Compensated Temporal Filtering (MCTF). In contrast, conventional still picture processing does not involve temporal filtering and thus no motion compensation between pictures. Because still cameras do not use MCTF, powerful still picture noise reduction is often implemented, especially when taking high ISO speed pictures. Because of the real time nature of video, such processing, even on dedicated hardware, can be too expensive to be practical. Moreover, still cameras have criteria that are difficult to meet simultaneously. For example, high speed capture and high quality powerful noise reduction.